干热河谷麻疯树访花昆虫及主要传粉昆虫

膏桐为一种重要的油料作物,其种子可以提炼生物柴油,生物柴油在我国将成长为有一定规模的产业。为了增加膏桐结籽率,提高其产量,给膏桐规模化栽培方面提供传粉生物学的科学依据,于2006年对云南元江坝区半栽培膏桐(Jatropha curcas L.)居群的访花昆虫及主要传粉昆虫种类进行调查。膏桐开花示样醒目,具花香与蜜腺,花形态没有特化,这些特征使得它提供的酬物适合于不同的昆虫采食,其访花昆虫种类较丰富,共有35种访花昆虫,分属5目20科。综合访花昆虫的传粉数量,及传粉质量包括访花行为、访花频率与日活动规律等确定主要传粉昆虫,确定大头金蝇Chrysomya(Compsomyia)megacephala Fabricius、中华蜜蜂Apiscerana Fabricius、迁粉蝶(淡色型)Catopsilia pomona f.Crocale为该居群的主要传粉昆虫。3种传粉昆虫具有不同的访花习性和日活动规律。雌雄迁粉蝶日活动规律相似。访花者的组成受气象因素、开花示样及生境条件的影响。最后,探讨膏桐与访花昆虫的关系,以及主要传粉者的组成随时空变异而改变的规律。

Foraging and main pollinators of Jatropha curcas in dry-hot valley

Jatropha curcas(L.) is an important oil crop to refine biodiesel from its seeds, and biodiesel will develop to an industry on a certain scale in China. In order to get a raise in its fruit set ratio, improve its yield, and provide scientific basis for large-scale planting, we investigated foraging insects and main pollintaing insects in the half-cultivated J. curcas population in Yuanjiang County, Yunnan Province in 2006. It was planted along a country road as a hedge on a flatland in Yuanjiang dry-hot valley. Near it were some economical crops including Mangifera indica L., Musa acuminata Colla, Jasminum sambac (L.) Ait., Saccharum sinense Roxb which provided good habitat for insects. The plant produced flowers in racemose inflorescences, with dichasial cyme pattern. The flowers of J. curcas were unisexual, and male and female flowers were produced in the same inflorescence which showed needing mates to help its pollination. Normally, the inflorescences produce 184±189.02(88～238)male flowers with bright yellow stamens. 9.94±29.58(0.21～21.57)of them open every day on the crown of the tree which make a great floral display. And both male and female flower produced flower odor and nectar. Its salver-shaped flower base promised many kinds of insect harvesting honey. There were amounted to 35 foraging insect species, belonging to 5 orders and 20 families. Half of them belong to Hymenoptera, while other belongs to Diptera, Lepidoptera, Hemiptera, and Coleoptera. By comparing the number and the pollination effectiviness (including their foraging behavior, foraging frequency, and daily activity rhythm)of the foragers, we determined the main pollination insects: Chrysomya (Compsomyia) megacephala Fabricius, Apis cerana Fabricius, and Catopsilia pomona f. Crocale. In addition, these species had different foraging behavior. The former two were smaller in body size than the honeybee, making them easy to transfer pollen from the stamens to the stigmas. But the honeybee was more numerous, compensated for its pollen-carrying ineffectiviness. The daily activity rhythm was different among three pollinators , and it showed identical between the male and female butterflies. Furthermore, the composition of foraging insects was influenced by the weather conditions, the floral display, and habitat conditions. Finally, we discussed the relationship between J. curcas and its foraging insects and concluded that the main pollinators were different with changed time and space.